I've read that the LA small block is limited to how high the compression ratio can be from the cylinder heads only having four bolts around each cylinder. And, this is why the racing blocks had six bolts around each cylinder. So, are there any tricks to make to stock LA small blocks with cast iron heads to bump the compression? Also, what's the highest compression I can get? Thanks.

What compression ratio do you want

You should be able to order pistons (custom if needed) to suit what you'd want I would imagine...

First off I am no expert,but I'll share what I know.Head studs if they can be used will increase clamping pressure(do you have room for these?).The next area to address are the gaskets,the method in the past was to o-ring the heads but there are gaskets available today that have an o-ring feature built in.What are you using the engine for?what are your goals and what fuel are you intending to use?

I'm just seeing what is obtainable. I want to build a high compression small block to race in the F.A.S.T. races. (Haven't decided whether I want a 340 or a 416) I haven't done enough research yet but I'm thinking I'll run E85 with an additive if that's possible. I'd want to be able to adjust the timing to run it on the street with E85 then use an additive w/E85 to race. I'm thinking 11.5:1 but hoping for 12.5:1 if that makes sense.

Do not run standard Fel Pro head gaskets. Fel Pro makes a light blue head gasket that is more for racing, about $50 a pair the last I bought. I run these in a turbocharged 340 with no problems.

You can also o ring the block yourself, just rent the tool from Iskerderian, pretty slick.

Studs help but check your headers --sometimes you need to "trim" the flange to clear the nuts--12 points help some on that --depends on the header--the Fel Pros with the ring built in are the 1008's use these vs. the other blue one they offer--I have run over 12:1 like this on a race unit for years but EXPECT to replace a gasket now and then on high compression SB's. I also like the Cometics and have had great luck with them. They can leak a little water but..McCandless always advised a warm up and retorque on SB's even with the 1008's. Keep an eye on your breathers and when you see a few beads--order a gasket--replace them before they go and treat it like std maintainence IMO

12.5 compression is nothing if you have closed chamber heads or quench top pistons. What ever you do "DO NOT USE Fel Pro 1008 GASKETS!!!!" I had 14:1 open chamber heads and it pushed the 1008's into the valley. I bought some gaskets from Dvorak in Florida and no more problems

Those orange jobs from Dan are available or were from Mopar as the "thinner" units--I think they are just Victors with orange color sealant--I have used them with success as well--Cheaper from Mopar or Victor by 1/2. Was a day when he was the only guy that had them but that did not last long and has been a while ago. Don't remember the part number but Wes at Mancini will have them if any place does.
I will still bet a hundred on slick decks and Cometics with spray Holomar and...you can reuse them several times--I have done it.